A storage system is a processing system adapted to store and retrieve information/data on storage devices, such as disks. The storage system includes a storage operating system that implements a file system to logically organize the information as a hierarchical structure of directories and files on the disks. Each “on-disk” file may be implemented as a set of disk blocks configured to store information, such as text, whereas each directory may be implemented as a specially-formatted file in which information about other files and directories are stored.
The storage operating system generally refers to the computer-executable code operable on a storage system that manages data access and access requests and may implement file system semantics in implementations involving storage systems. In this sense, the Data ONTAP® storage operating system, available from Network Appliance, Inc. of Sunnyvale, Calif., which implements a Write Anywhere File Layout (WAFL®) file system, is an example of such a storage operating system implemented as a microkernel within an overall protocol stack and associated disk storage. The storage operating system can also be implemented as an application program operating over a general-purpose operating system, such as UNIX® or Windows®, or as a general-purpose operating system with configurable functionality, which is configured for storage applications as described herein.
A storage system's disk storage is typically implemented as one or more storage volumes that comprise physical storage disks, defining an overall logical arrangement of storage space. Available storage system implementations can serve a large number of discrete volumes such as 150 or more, for example. A storage volume is “loaded” in the storage system by copying the logical organization of the volume's files, data, and directories, into the storage system's memory. Once a volume has been loaded in memory, the volume may be “mounted” by one or more users, applications, devices, and the like, that are permitted to access its contents and navigate its namespace. As used herein, a volume is said to be “in use” when it is loaded in a storage system's memory and at least one user, application, etc., has mounted the volume and modified its contents.
A storage system may be configured to allow client systems to access files stored on a storage system. In this model, the client may comprise an application executing on a computer that “connects” to the storage system over a computer network, such as a point-to-point link, shared local area network (LAN), wide area network (WAN), or virtual private network. (VPN) implemented over a public network such as the Internet. Communications between the storage system and its clients are typically embodied as packets sent over the computer network. Each client may request the services of the storage system by issuing file-system protocol messages formatted in accordance with a conventional file-system protocol, such as the Common Internet File System (CIFS), Network File System (NITS) protocol, Fibre Channel Protocol (FCP), Internet Small Computer System Interface (iSCSI), or Storage Area Network (SAN) access.
In general, a computer system (e.g., storage system or client) may receive and transmit data over a network by implementing one or more network devices/cards operated by a device driver residing and executing on the operating system of the computer system. Although network devices may be hardware capable of full duplex operation (i.e., hardware designed to provide simultaneous receiving and transmitting of data), network devices are not conventionally implemented in software (through the operating system and the device driver) to provide full duplex capabilities. As such, there is a need for a software implementation of network devices that provide full duplex operation of the network devices to operate the network devices to their fullest capacities and to increase network data throughput.